The “INESA Lighting Handbook” published by the Illuminating Engineering Society of North America, is incorporated by reference here in its entirety. As discussed in chapter seven of that handbook, a “luminaire” is a device for producing, controlling, and distributing light. It is typically a complete lighting unit consisting of one or more lamps, sockets for positioning and protecting the lamps and for connecting the lamps to a supply of electric power, optical devices for distributing the light, and mechanical components for supporting or attaching the luminaire. Luminaires are also sometimes referred to as “light fixtures.”
“Diffused lighting” luminaires generally provide light on a work plane or an object that is not incident predominantly from any particular direction. “Direct-Indirect lighting” is a variant of general diffused lighting in which luminaires emit little or no light at angles near the horizontal. For example, Cooper Lighting of Peachtree City, Ga. offers a variety of suspended direct-indirect fluorescent luminaires under its Corelite brand which are well suited for open offices, private offices, conference rooms, trading floors, reception area, and educational facilities. Specification sheets and installation instructions for those luminaires are available at www.cooperlighting.com and are incorporated by reference here.
Shutters have also been used to control light eminating from a luminaire and are typically moveable covers or screens that alternately prevent or permit the passage of light. For example, U.S. Pat. No. 5,293,306 is incorporated by reference here and discloses a lantern with a shutter that can be closed in order to prevent light from shining through one side of the lantern. U.S. Pat. No. 4,530,041 is also incorporated by reference here and discloses a signal lamp with a slit-plate that is slidably positioned across the opening of a lamp housing in order to control light from the lamp. A variety of other lighting control techniques are also disclosed in U.S. Pat. Nos. 5,313,380, 4,468,720, 4,499,529, 6,206,581, 4,323,955, and 5,733,036, each of which is incorporated by reference here in its entirety.